Yeah as far as I know, everything from the dash forward should be the same as the coupes. Gaurds, bonnet, front bar, lights etc. If they're the same series.
http://www.1010tires.com/WheelOffsetCalculator.asp
That's the calculator. Type in what you have and what you want. Just experiment with different width and offsets to find out which one you like best.
If you're worried about your wheels not fitting, try using the offset calculator. Just type in your wheels at the moment and type in the wheels you want. It will tell you how much the wheel will stick out from where it is now.
You can fit a GTR bonnet with any headlight. The only difference would be that some don't have the brackets to hold the grille on. As long as you modify/change your bonnet latch, a GTR bonnet will fit.
I would say that if you rarely 'use' your car then it wouldn't be worth the time or money, but if you're going to take it on the track or do some runs, go for it.
Your tyres have to be the same width because if they're not, it can stuff up your attessa. I'm not too sure on whether you can run the same width tyres on a different width rim.
The genuine N1 headlights (no projector) had brackets to hold the GTR's grille on while the other non projector headlight don't have the brackets? I'm assuming they're the only difference because I'm pretty sure those 'lower spec normal' ones don't have these brackets and the GTR's need them to hold the grille on.
Not to sound like an ass, but why wouldn't a GTS-T one fit a GTR? I understand why you weren't sure on the rear bar, but the gear boot?
I'm going to take a guess and say that they're the same because I never knew there was a difference.
Sorry if this post didn't help you in any way
http://www.chris-longhurst.com/carbibles/tyre_bible_pg2.html
Scroll down to where they compare wide and thin tyres. It explains what I was trying to say in my other post.
I'm just assuming that the speedo cable is the problem. You can get speedo cables from wreckers, but they could be stuffed aswell. Best to get one new from Nissan. I think it was about $100.
You can get a second hand heater core from your local wrecker, but you never know, it could be stuffed too.
The heater core is located at the back of the dash. You're going to need to take out the whole dash as far as I know.
I would think that it's a fuse problem. Two things going out at the same time.....
There's a thread somewhere here on sau to show you what those Jap words on the fuse cover means. I remember getting the info from somewhere on here. Quick search and you'll find it.
It sounds like your heater core is stuffed or your hoses have come off. Summer's coming up so there's no need for the heater. Just unplug the hose that goes to your heater from the engine bay.
I haven't bought anything from SK, but when I've asked him questions I wasn't too sure of, he was happy to answer ALL of them. Not sure what he's up to at the moment, but I don't think he's dodgey.